Tailor-made microbes could save thousands of lives a year in poor nations, but not in the way you would think. A new breed of bioengineered bacteria can spot buried explosives.

A group of students at the University of Edinburgh have engineered a bacteria that glows bright green when it comes in contact with the chemicals that leech into the soil from buried explosives. The bacteria could be mixed into a colorless solution, and sprayed over the minefield from the air, showing bright green after a few hours. This would be a great improvement over the current slow, and decidedly dangerous methods of finding mines in existing mine fields. The students who created the bacteria say it is cheap to produce, and harmless to humans and animals, though they didn't mention its effects on local plant life.

The developers explain:

We suggest that the bacteria are dropped from a low flying aircraft which will evenly disperse the bacteria across the expected landmine field. This will allow the ground to be covered in the bacteria which will then respond to any TNT or Nitrites that it discovers in the soil. After darkness, which will give the bacteria enough time to produce the proteins which emit light and EYFP, a plane could then fly over the area once again and mark down the location of any luminescence found in the soil, for further investigation. This will provide a much safer method than having a person in the field detecting the landmines.

The bacteria will be engineered with a "kill switch" will turn off their luminescence after a few hours.

While the developers of the mine sensing bacteria have no plans to commercialize their discovery, they noted that the substance would cost approximately £0.013 per square meter where it is sprayed. So this is could be a fairly low-cost solution too, depending on the size of affected areas.

The bacteria were created for the iGem contest using a technique known as BioBricking. BioBricks are chunks of DNA sequence, each of which has a known function, and can be combined with others. It's like nanoscale biological lego: each piece has a specific function, and when combined with other pieces, the larger unit retains connectivity, so it can then be fitted onto other BioBricks. It's a technique that was developed by MIT in 2003, as a way of providing a library of biological parts, with the long-term goal of producing a synthetic living organism from standard parts.